1. Field of the Invention
This invention relates to an apparatus and a method for mounting a tape carrier package onto a liquid crystal display.
2. Prior Art
Before mounting a TCP (Tape Carrier Package) onto an LCD (liquid crystal display), the positional relationship between the TCP and LCD is monitored by a camera. And, if any positional dislocation is found between them, it is necessary to eliminate such a dislocation. In general, the LCD and TCP are provided with numerous thin electrodes and leads arrayed along the sides thereof at very small pitches. The number of such electrodes and leads will range from several tens to several hundreds. Thus, the mounting of these LCD and TCP requires an extremely high accuracy in X and Y directions.
As a method for monitoring the mutual positional relation between a TCP and an LCD, there are known the following two methods.
A first method uses a camera whose visual field is stationarily fixed for assuring accuracy in the recognition of these components. The LCD and the TCP are supported movable in the X-Y direction (i.e. along a horizontal plane). Then, the LCD and the TCP come in the visual field of the camera but they are not overlapped. Under this condition, a mutual positional dislocation is obtained through image analysis. Thereafter, both are shifted to correct the mutual relation. Then, the mounting operation is performed by overlapping the TCP onto the LCD.
A second method is carried out in the following manner. First, a TCP and an LCD are overlap each other with a very small gap, so that the mounting operation is soon accomplished by lowering the TCP onto the LCD by a very small distance. This overlapped condition is monitored by a camera to detect a dislocation between the TCP and the LCD.
However, it is usual that anisotropic conductive tapes are attached on electrodes of the LCD to adhesively bond the electrodes to the leads of the TCP. Thus, these anisotropic conductive tapes and the LCD itself may become obstacles when the leads of the LCD are monitored by the camera according to the above first and second methods. Thus, there is the possibility that these first and second methods may fail to obtain a clear image of the TCP, and therefore the detected position of the TCP may be inaccurate, resulting in deterioration of accuracy in the mounting operation. If the obtained image is unclear, the image analysis will encounter with errors so frequently that the mounting operation of the TCP is substantially stopped or suspended.